100 Greatest Discoveries: Chemistry

Chemistry is a fascinating subject. So much information has been discovered, yet there is still so much more information to learn. Throughout history many groundbreaking discoveries have been made. It started back in ancient Greece. The Greeks thought there were only four elements: earth, air, fire, and water. Leonardo Da Vinci challenged that idea and said that air was composed of two different substances. This led to the discovery of oxygen. Joseph Priestley was searching for new air (gases). He conducted experiments with liquid mercury. Antoine Lavoisier also experimented with oxygen. Joseph Priestley discovered oxygen, but Antoine Lavoisier invented it. Next, the atomic theory was invented by John Dalton. He thought that everything was made of smaller pieces called atoms. Amedeo Avogadro quashed the assumption that gases were made of one atom. He suggested that atoms combine into molecules. The synthesis of urea was definitely mind-blowing. By combining inorganic elements, an organic element is created. This organic element is found in life. Perhaps this is the secret of life Victor Frankenstein used when creating his monster. August Kekule was an important chemist that thought that the chemical structure of an element was essential. Everyone thought that the structure of every molecule was a straight chain, but Kekule discovered that Benzene was shaped like a ring. Dimitri Mendeleev is one of the most genius chemists in history. He created the periodic table. This is the image that everyone associates with chemistry. It all started when he was trying to teach his class about different elements. He laid out cards for the different elements on his desk. The cards had the properties of the elements on them. Dimitri grouped the cards in rows and columns based on their similarities. Mendeleev was able to predict properties of elements that had not even been discovered! Next, Humphry Davy set the path for electrochemistry. He performed an experiment with potash. Electrochemistry is used everyday in the modern world. Some examples are the aluminum industry, rechargeable lithium batteries, and solar panels. Next, atoms were discovered to have signatures of light. When elements are added to fire, the color of the flame changes. Sodium changes a flame to orange. Copper changes a flame to green. Strontium changes a flame to red. Joseph Thompson made a revolutionary discovery about atoms. By using what he called a “crookes tube,” a stream of electrons was displayed. Thus, the electron was discovered. Gilbert Lewis then came up with the theory that electrons went around atoms as shells. When electrons were exchanged, new chemicals were formed. For example, sodium and chlorine on their own are toxic, but when combined, they produce everyday table salt. Soon, fullerenes were discovered. They are carbon nanotubes that are one-billionth of a meter in diameter. These are smaller than DNA! In conclusion, chemistry is constantly changing as new things are being discovered or proven.